This invention relates generally to hand tools and, more particularly, to a hand operated tool for inserting intramedulary pins into fractured bones of humans and animals.
In medical practice, it has become customary in certain situations to insert stainless steel pins into bone structure during orthopedic treatment. This may be accomplished by a physician operating upon a human or by a veterinarian operating upon an animal in those instances where it is desirable to provide internal support or fixation for the fractured bone.
For this purpose, hand tools have been employed to insert the steel pins into the bones or lined-up fragments of bones to be joined. The pin is inserted into a cavity within the bone called the medulary or marrow cavity. The bone subsequently heals around the pin but the pin served to stabilize the bone fragments while permitting the animal or human patient limited use of the limb so joined.
It has been the practice to insert intramedulary pins by means of a tool which firmly clamped the pin but required the operator to manually twist or rotate the tool and, with it, the pin as longitudinal force was applied to the tool. This combined action of longitudinal force on the pin together with its simultaneous rotation has been found to be of distinct advantage in the procedure of inserting pin into the bone marrow. However, such combined manual action made it difficult for the operator to assure that the pin was maintained in a desired direction as it advanced longitudinally. Rather, it often resulted in a wobbling motion which would adversely affect the final positioning of the bones being joined and would also result in drilling a hole in the bone of larger diameter than desired or needed to receive the pin.
In most instances, the hand tools previously employed did not allow for wide varieties of diameters and lengths of pins. Furthermore, they were usually of a complicated design which caused them to be expensive to fabricate and maintain. Additionally, tools of this type which have been used previously could not be readily disassembled for purposes of cleaning and sterilization and oftentimes required lubrication which further impeded such efforts.